Electric pneumatic shift control

ABSTRACT

A means for controlling a transmission from either one of a pair of operator stations. A multi-position cylinder conditions the transmission for a given direction of travel and speed range. Air pressure is directed to various chambers within the cylinder to achieve the desired position by a plurality of solenoid-operated valves. The valves are selectively energized by a circuit means, including a switch means located in each of the operator stations. A selector switch in one station selectively connects one of the switch means with a source of electrical energy.

United States Patent Luft et al.

ELECTRIC PNEUMATIC SHIFT CONTROL 3,512,277 5/1970 Stuller 180/77 R X[75] Inventors: Robert G. Luft, Wildwood; LeRoy G. I-Ialvorson,lngleside, both of 111. Prlma'y McKem Attorney, Agent, or Firm-Ronald C.Kamp; Floyd B. [73] Assignee: International Harvester Company, HarmanChicago, Ill. [22] Filed: Apr. 13, 1972 [57] ABSTRACT [2l] Appl. No.:243,722 A means for controlling a transmission from either one of a pairof operator stations. A multi-position cylinder conditions thetransmission for a given direction Ill. of travel and Speed range. Airpressure is directed to [58] Fie'ld 180/77 S various chambers within thecylinder to achieve the desired position by a plurality ofsolenoid-operated 56] Reerences cued valves. The valves are selectivelyenergized by a circuit means, including a switch means located in eachUNHED STNI PATEN] 5 of the operator stations. A selector switch in onesta- 3,679.0l3 7/1972 u t v l 180/77 3 tion selectively connects one ofthe switch means with Bechman et Ell. a source of electrical energy3,386,316 6/1968 Armantrout 74/870 3,487,725 1/1970 Brunot 74/870 X 7Claims, 1 Drawing Figure 70 0 IV. ARM 68 F/w/vr M 5 $74710 1P 2TRANSMISSION 64 1g 51 mks/firm? I F a- 22 3 1 5 0 54 X rM/vsH/ss/o/v XXgg lll o fill/F7071. 7-0 0:515 0 98 I 48 3 P 46 a 56 58 PEAPNSTATIOIV 14A B D E F 62 74 R(n vo) mm) X X X M ./\96' 92 REV) x X 44 i R Re s Evan?ELECTRIC PNEUMATIC SHIFT CONTROL CROSS REFERENCE TO RELATED APPLICATIONThis application is related to that disclosed and claimed in theapplication of Robert G. Luft entitled DUAL STATION TRANSMISSIONCONTROL, Ser. No. 52,938 now US. Pat. No. 3,679,018 filed July 7, 1970.

BACKGROUND AND SUMMARY OF THE INVENTION The aforementioned patent fullydescribes some of the reasons for and necessity of an arrangement forcontrolling a transmission from two different operator stations. It isan object of this invention to provide a dual station control for atransmission which is simple, inexpensive and reliable, and in which thenumber and length of fluid conduits are minimized, the use of aplurality of common standard components is maximized, and the need forspecially constructed cams and the like is eliminated. It is also anobject of this invention to provide a control means having theaforementioned attributes for control of a transmission, and especiallya transmission of the automatic type, from a single station.

These and other objects and many of the attendant advantages of thepresent invention will become more readily apparent upon a perusal ofthe following description and the accompanying drawing, wherein the solefigure is a schematic diagram of a transmission control incorporatingthe invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing,there is shown a front station or operator compartment 12 and a rearstation 14. A selector switch 16 is provided in the front station 12 andis connected with a source of electrical energy, such as a battery 18,by means of conductor 20, The switch 16 is of the two-position type andin its FRONT position, is illustrated in the drawing, connects thebattery 18 with a conductor 22. The conductor 22 communicates with atransmission control switch means 24 which comprises seven single polesingle throw switches. These switches are closed by a cable controlmeans 26 which is actuated by a manual handle 28 located in the frontstation l2.

Considering now the individual switches, the N switch is closed when thehandle 28 is positioned in its neutral position and directs electricalenergy to the starter circuit through the conductor 30. When the Rswitch is closed by moving the handle 28 to its reverse position,electric energy is directed through conductors 32 and 80 to actuate thesolenoids of valve 34 and through conductors 36 and 38 to actuate thesolenoids of valves 40 and 42 respectively. These valves 34, 40 and 42are spring biased to the position shown in the drawing and are shiftedby their solenoids to direct air pressure from the reservoir 44 to therespective ports A, B and D of the shift cylinder 46. The shift cylinderis of the multiposition type having a plurality of chambers to which airpressure may be selectively directed to control the degree of extensionof the rod 48 in the cylinder, and may, for example be of the typesoldby Westinghouse Air Brake Co. and identified as their 2X3M4-N-2BCylinder Assembly.

The rod 48 of the cylinder is linked to a bellcrank 50, which in turn isconnected to gear shift arm 52 of the transmission 54 by means of link51. The gear shift arm 52 is connected to a conventional type oftransmission conditioning mechanism, such as a valve spool for directinghydraulic pressure to the proper clutch packs within the transmissionfor achieving the designated direction and speed range gear changes. Forreverse gear the pressuring of ports A, B and D will extend the rod 48of the cylinder 46 the proper amount to move the gear shift arm 52 tocondition the transmission for low speed in a reverse direction.

When the handle 28 is moved to its 1 position for low gear in a forwarddirection the switch identified as 1 will be closed. Electrical energywill be transmitted through the conductors 56 and 58 to actuate thesolenoids of valves 60 and 62 respectively. Energizing the solenoidscauses the valves 60 and 62 to shift against the bias of their springsdirecting air pressure from the reservoir 44 to the port E of the shiftcylinder 46 and to the port F of the slave cylinder 64. The rod 66 ofthe slave cylinder 64 includes a plunger 68 which is capable, in itsextended position, of moving the throttle valve arm associated with thetransmission 54, which is of the automatic type in that it willautomatically shift to higher gears as engine speed increases and theload encountered permits, and will shift down as the engine throttlecontrol is moved to accelerate the engine or when load encountered lugsthe engine down. The rod 66 and its plunger 68 is normally biased to aretracted position, but when air pressure is introduced through port Fthe rod 66 is extended causing the throttle valve arm 70 to be movedwhereby the transmission 54 receives the same signal or indication itwould if the operator were attempting to rapidly increase engine speed.Hence, the transmission 54 will be prevented from shifting up, i.e.,shifting from first gear to a higher gear. The air pressure directed toport E of the shift cylinder 46 will have shifted the rod 48 to positionthe arm 52 at the position indicated l-2 so that the transmission isconditioned for first gear in a forward direction, with the capabilityof shifting to second gear but for the fact that the throttle valve arm70 has been moved to prevent the automatic shift to second gear.

When the handle 28 is moved to a position to close the switch indicatedl-2, electrical energy will be directed through conductor 72 causing thesolenoid of valve 60 to be actuated. Valve 60 will be shifted directingair pressure from the reservoir 44 to the port E. The transmission gearshift arm 52 will be positioned as previously described at the 1-2position. Now, however, the diode 74 will prevent actuation of thesolenoid of valve 62 and the plunger 68 will be retracted by the springbiased slave cylinder 64 and the throttle valve arm 70 can perform itsnormal function, permitting the transmission 54 to shift to second gearwhen conditions permit.

When the handle 28 is positioned to close the switch indicated as 3-4,the conductor 76 is energized causing the solenoid of valve 60 to beactuated. Simultaneously, the diode 78 permits the conductor 80 to beenergized and the solenoid of valve 34 actuated. Air pressure is therebydirected to the ports A and E of the shaft cylinder 46. The rod 48 willbe extended on a point to position the arm 52 at the 3-4 position. The

transmission 54 will therefore be conditioned to operate in either thirdor fourth gear in a forward direction depending upon conditions. Thediodes 74, 82 and 84 prevent any of the other solenoids being actuated.

Closing the switch indicated as 3-5 by moving the handle 28 energizesthe conductor 86 and actuates the solenoid of valve 40. The diode 82also permits the solenoid of valve 60 to be actuated and diode 78,permits the solenoid of valve 34 to be actuated. Air pressure is,therefore, directed to ports A, B and E of shift cylinder 46 and its rod48 moved to position the arm 52 as indicated at 3-5. The transmission 54will thereby be conditioned to automatically shift to any one of third,fourth or fifth gears on a forward direction depending upon conditions.

Similarly, movement of handle 28 to its 3-6 position will close theswitch indicated as 3-6, causing the conductor 88 to be energized andthe solenoid of valve 42 to be actuated. Air pressure is directed toport D of the shift cylinder 46. The rod 48 will be extended to positionthe arm 52 at 3-6. The transmission 54 will be conditioned toautomatically shift to any one of third, fourth, fifth and sixth gears,conditions permitting, in a forward direction.

The station selector switch 16, when moved to its rear position,isolates the switch 24 from the battery 18 and connects the conductor 20with the conductor 90 leading to the wiper of a switch 92 in therearstation 14. The front station 16 is rendered inactive and the rearstation 16 now has control over the transmission 54. In order to drivethe vehicle in a forward direction from the rear station 14 the switch92 is moved to its R position. The conductor 90 is thereby connectedwith a conductor 94 which connects with the conductor 32. Energizingconductor 32 functions to actuate the solenoids of valves 34, 40 and 42which conditions the transmission 54 for reverse drive as describedpreviously. Movement of the switch 92 to its 1 position will cause thevehicle to move in a reverse direction with respect to the rear station.The conductor 90 is connected with a conductor 96 which connects withthe conductor 56. Energizing the conductor 56 will cause the solenoidsof valves 60 and 62 to be actuated which conditions the transmission 54for forward drive as described previously.

The diodes 98 and 100 serve to insure isolation of the switch 92 fromthe battery 18 whenever the selector switch 16 is in its FRONT position.Similarly, the diodes 102, 104, 106 and 108 insure that the switch 24can exercise no control over the transmission 54 whenever the selectorswitch 16 is in its REAR position. The remaining diodes within thecircuit means, indicated generally at 110, are for the purpose ofinsuring that only the desired ones of the solenoids, as previouslydescribed, are actuated. These diodes are conventional and considerationneed be given only the power transmission requirements of each tofulfill optimum costperformance design criterion.

While a preferred embodiment of the present invention has beenillustrated and described herein, it is to be understood that variouschanges and modifications may be made without depending from the spiritof the invention as defined by the scope of the appended claims.

What is claimed is:

l. A control means for a transmission having a shift arm capable ofbeing moved between a plurality of positions, each of said positionsconditioning the transmission for a given direction and speed range,comprising:

a multiposition shift cylinder operatively connected to the shift armfor moving said arm to its said positions;

said cylinder having a plurality of ports which, when selectivelypressurized, cause said cylinder to move to each of its multipositions;

a solenoid-actuated valve communicating with each of said ports andcapable, when energized, of directing fluid pressure thereto;

circuit means including a first manually actuated switch means forselectively energizing certain ones of said valves to extend saidcylinder to a desired one of its multipositions.

2. A control for a transmission according to claim 1 and furthercomprising;

a second manually actuated switch means for selectively energizing atleast a portion of said circuit means; and a selector switch forselectively energizing one of said first and second switch means. 3. Acontrol means according to claim 2, wherein the transmission is capableof automatically shifting from a high gear to a lower gear underconditions of acceleration, and further comprising:

a throttle valve arm connected with said transmission to condition saidtransmission for said lower gear under conditions of acceleration;

a fluid cylinder engageable with said arm and movable under theinfluence of fluid pressure to move and maintain the throttle valve armin the position it would assume under said acceleration condifluidpressure to said cylinder;

circuit means, including a first manually actuated switch means, forselectively energizing the desired ones of said valves to orient saidcylinder to initially 5O condition the transmission for said low gear;and

means operable upon energization of a certain one of said valves toprevent said transmission from shifting to a higher gear.

5. A control according to claim 4 wherein said last mentioned meanscomprises;

a throttle valve arm connected with said transmission to insure thetransmission is conditioned for said low gear under conditions ofacceleration;

a fluid cylinder engageable with said arm and movable under theinfluence of fluid pressure received from said certain valve to move andmaintain the throttle valve arm in the position it would assume undersaid acceleration conditions.

6. A control according to claim 5, and further comprising:

a second manually actuated switch means for selectively energizing atleast a portion of said circuit means; and

a fluid cylinder engageable with said arm and movable under theinfluence of fluid pressure to move and maintain the throttle valve armin the position it would assume under said acceleration conditions; andmeans for selectively directing fluid pressure to said cylinder.

1. A control means for a transmission having a shift arm capable ofbeing moved between a plurality of positions, each of said positionsconditioning the transmission for a given direction and speed range,comprising: a multiposition shift cylinder operatively connected to theshift arm for moving said arm to its said positions; said cylinderhaving a plurality of ports which, when selectively pressurized, causesaid cylinder to move to each of its multipositions; a solenoid-actuatedvalve communicating with each of said ports and capable, when energized,of directing fluid pressure thereto; circuit means including a firstmanually actuated switch means for selectively energizing certain onesof said valves to extend said cylinder to a desired one of itsmultipositions.
 2. A control for a transmission according To claim 1 andfurther comprising; a second manually actuated switch means forselectively energizing at least a portion of said circuit means; and aselector switch for selectively energizing one of said first and secondswitch means.
 3. A control means according to claim 2, wherein thetransmission is capable of automatically shifting from a high gear to alower gear under conditions of acceleration, and further comprising: athrottle valve arm connected with said transmission to condition saidtransmission for said lower gear under conditions of acceleration; afluid cylinder engageable with said arm and movable under the influenceof fluid pressure to move and maintain the throttle valve arm in theposition it would assume under said acceleration conditions; and meansfor selectively directing fluid pressure to said fluid cylinder.
 4. Acontrol for an automatic transmission capable of automatically shiftingfrom a low gear to a higher gear comprising: a multiposition shiftcylinder operatively connected to and capable of initially conditioningthe transmission for said low gear; a plurality of solenoid-operatedvalves for directing fluid pressure to said cylinder; circuit means,including a first manually actuated switch means, for selectivelyenergizing the desired ones of said valves to orient said cylinder toinitially condition the transmission for said low gear; and meansoperable upon energization of a certain one of said valves to preventsaid transmission from shifting to a higher gear.
 5. A control accordingto claim 4 wherein said last mentioned means comprises; a throttle valvearm connected with said transmission to insure the transmission isconditioned for said low gear under conditions of acceleration; a fluidcylinder engageable with said arm and movable under the influence offluid pressure received from said certain valve to move and maintain thethrottle valve arm in the position it would assume under saidacceleration conditions.
 6. A control according to claim 5, and furthercomprising: a second manually actuated switch means for selectivelyenergizing at least a portion of said circuit means; and a selectorswitch for selectively energizing one of said first and second switchmeans.
 7. A control for an automatic transmission driven by an engine,which transmission is capable of shifting from a high gear to a lowergear under conditions of acceleration of the engine, comprising: athrottle valve arm connected with said transmission to condition saidtransmission for said lower gear under conditions of acceleration; afluid cylinder engageable with said arm and movable under the influenceof fluid pressure to move and maintain the throttle valve arm in theposition it would assume under said acceleration conditions; and meansfor selectively directing fluid pressure to said cylinder.